# 2. Authentication

const crypto = require('crypto');

function generateChallengeSignature(installationId, appSecret) {
  return crypto
    .createHmac('sha256', appSecret)
    .update(installationId)
    .digest('hex');
}

// Example usage
const installationId = 'c314c1d8-41c8-492f-aadd-8f2c5cd59b07';
const appSecret = 'your_app_secret_here';
const challengeSignature = generateChallengeSignature(installationId, appSecret);

console.log(challengeSignature);

import hmac
import hashlib

def generate_challenge_signature(installation_id: str, app_secret: str) -> str:
    return hmac.new(
        app_secret.encode('utf-8'),
        installation_id.encode('utf-8'),
        hashlib.sha256
    ).hexdigest()

# Example usage
installation_id = 'c314c1d8-41c8-492f-aadd-8f2c5cd59b07'
app_secret = 'your_app_secret_here'
challenge_signature = generate_challenge_signature(installation_id, app_secret)

print(challenge_signature)

package main

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
)

func generateChallengeSignature(installationID, appSecret string) string {
	h := hmac.New(sha256.New, []byte(appSecret))
	h.Write([]byte(installationID))
	return hex.EncodeToString(h.Sum(nil))
}

func main() {
	installationID := "c314c1d8-41c8-492f-aadd-8f2c5cd59b07"
	appSecret := "your_app_secret_here"
	challengeSignature := generateChallengeSignature(installationID, appSecret)
	
	println(challengeSignature)
}

<?php

function generateChallengeSignature($installationId, $appSecret) {
    return hash_hmac('sha256', $installationId, $appSecret);
}

// Example usage
$installationId = 'c314c1d8-41c8-492f-aadd-8f2c5cd59b07';
$appSecret = 'your_app_secret_here';
$challengeSignature = generateChallengeSignature($installationId, $appSecret);

echo $challengeSignature;
?>

require 'openssl'

def generate_challenge_signature(installation_id, app_secret)
  OpenSSL::HMAC.hexdigest('SHA256', app_secret, installation_id)
end

# Example usage
installation_id = 'c314c1d8-41c8-492f-aadd-8f2c5cd59b07'
app_secret = 'your_app_secret_here'
challenge_signature = generate_challenge_signature(installation_id, app_secret)

puts challenge_signature

using System;
using System.Security.Cryptography;
using System.Text;

public static string GenerateChallengeSignature(string installationId, string appSecret)
{
    using (var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(appSecret)))
    {
        byte[] hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(installationId));
        return BitConverter.ToString(hash).Replace("-", "").ToLower();
    }
}

// Example usage
string installationId = "c314c1d8-41c8-492f-aadd-8f2c5cd59b07";
string appSecret = "your_app_secret_here";
string challengeSignature = GenerateChallengeSignature(installationId, appSecret);

Console.WriteLine(challengeSignature);

import * as crypto from 'crypto';

function generateChallengeSignature(installationId: string, appSecret: string): string {
  return crypto
    .createHmac('sha256', appSecret)
    .update(installationId)
    .digest('hex');
}

// Example usage
const installationId = 'c314c1d8-41c8-492f-aadd-8f2c5cd59b07';
const appSecret = 'your_app_secret_here';
const challengeSignature = generateChallengeSignature(installationId, appSecret);

console.log(challengeSignature);

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;

public class HmacGenerator {
    public static String generateChallengeSignature(String installationId, String appSecret) throws Exception {
        Mac hmacSha256 = Mac.getInstance("HmacSHA256");
        SecretKeySpec secretKey = new SecretKeySpec(appSecret.getBytes(StandardCharsets.UTF_8), "HmacSHA256");
        hmacSha256.init(secretKey);
        
        byte[] hash = hmacSha256.doFinal(installationId.getBytes(StandardCharsets.UTF_8));
        
        StringBuilder hexString = new StringBuilder();
        for (byte b : hash) {
            String hex = Integer.toHexString(0xff & b);
            if (hex.length() == 1) hexString.append('0');
            hexString.append(hex);
        }
        return hexString.toString();
    }
    
    public static void main(String[] args) throws Exception {
        String installationId = "c314c1d8-41c8-492f-aadd-8f2c5cd59b07";
        String appSecret = "your_app_secret_here";
        String challengeSignature = generateChallengeSignature(installationId, appSecret);
        
        System.out.println(challengeSignature);
    }
}

const std = @import("std");
const crypto = std.crypto;

fn generateChallengeSignature(
    allocator: std.mem.Allocator,
    installation_id: []const u8,
    app_secret: []const u8,
) ![]u8 {
    var hmac: crypto.auth.hmac.sha2.HmacSha256 = crypto.auth.hmac.sha2.HmacSha256.init(app_secret);
    hmac.update(installation_id);
    
    var hash: [32]u8 = undefined;
    hmac.final(&hash);
    
    var hex_string = try allocator.alloc(u8, 64);
    _ = try std.fmt.bufPrint(hex_string, "{x}", .{std.fmt.fmtSliceHexLower(&hash)});
    
    return hex_string;
}

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();
    
    const installation_id = "c314c1d8-41c8-492f-aadd-8f2c5cd59b07";
    const app_secret = "your_app_secret_here";
    
    const challenge_signature = try generateChallengeSignature(allocator, installation_id, app_secret);
    defer allocator.free(challenge_signature);
    
    std.debug.print("{s}\n", .{challenge_signature});
}